All I can say is that what I have been doing for the last 15 years is working for me. Marek\'s was introduced here by a purchased bird in the early 1990\'s. I didn\'t know what was going on until I lost the buff Ameraucana bantam pullet that won best AOCCL at the 1996 APA national meet held in Minnesota the following December, along with her best pullet sibling. With that heartbreaking loss I realized what the problem had to be since they were very healthy in every other respect. Since starting the vaccination program losses have been very minimal. I quarter the wafer, drop 1/4 in an empty diluent bottle, pour in 1/4 of a bottle of chilled diluent, cap it, shake it up, pour it into a clean shot glass, draw a couple of syringes, shoot them down the drain, and commence vaccinating. Air bubbles are not a problem. If I get one, I simply discharge the dose back into the shot glass and draw a different one. I also give a little more than the recommended dose since I always end up with extra to throw away anyway. It works. Most of the time I am only vaccinating from 20 to 50 chicks, so there is no way I\'m spending the extra money to use up a whole wafer each time.